Piston engine over-torque? Is it possible? Never heard of it?
While reviewing the maintenance log sheets at the company where I work flying turbine helicopters, I noticed that there are two pilot groups who have an excessively high number of over-torques. I have learned that they are from two very different back-grounds. They have either come up the civilian side where they have never been taught what an over-torque is with regard to piston helicopters, and have therefore not been taught the importance of observing the indicator. The other group of pilots are from the military; those who have been flying large aircraft with significant disposable horsepower. This group has simply become complacent in their technique and do not maintain a good instrument scan thereby not knowing how much torque they are pulling. In either case, these pilots exhibit poor skills and technique.
With regard to a piston engine, the torque limit indicator is the manifold pressure gauge. I guess even some flight instructors don't know this, and therefore don't teach it. You have to wonder how that began to be passed on. I know I was taught that the manifold pressure gauge was a limitation, but was not taught to heed the limitation. Now days it seems that student pilots are just taught to pull whatever it takes to get the job done. I have heard some state that there is a fudge factor built in anyway. THIS IS NOT TRUE!
The piston engine manifold pressure gauge is the counterpart to the turbine engine torque meter, and should be used in exactly the same way. They are both limitations and must be closely monitored and respected as such.
In the training environment, it has become common place to over fuel piston aircraft causing an over-gross situation, which is further compounded by disregard of the manifold pressure limitation. Nothing screams poor pilot like one who disregards limitations. Pilots who are taught proper procedure and respect of limitations from the beginning will not have over-torque issues when they make the transition to turbine helicopters later in their career. END.